Method of forging choker hooks



y 6, 1955 R. E. TIMBERLAKE 3,192,760

METHOD OF FORGING CHOKER HOOKS Filed Dec. 29, 1960 5 Sheets-Sheet 1 IN VEN TOR. Rea 275 finneuox:

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y 6, 1965 R. E. TIMBERLAKE 3,192,760

METHOD OF FORGING.CHOKER HOOKS Filed Dec. 29, 1960 3 Shgecs-Sheet 2INVENTOR. Rosa-RTE finaakuxs BY 612M drrqmvers y 6, 1965 R. E.TIMBERLAKE 3,192,760

METHOD OF FORGING CHOKER Hooxs Filed Dec. 29. 1960 3 Sheets-Sheet 3INVENTOR. ROGERTE TIMBERMKE.

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United States Patent Office 3,192,?h Fatented July 6, 1965 3,192,760METHOD OF FORGING CHUKER HOOKS Robert E. Timberlake, Cumberland Center,Maine, assigner to American Hoist & Derrick Company, St. Paul, Minn acorporation of Minnesota Fiied Dec. 29, 1960, Ser. No. 79,362 2 Claims.(Cl. 72-641) The present invention has relation to traveling chokerhooks and more particularly to a method of making forged travelingchoker hooks and an apparatus for performing this method.

Traveling choker hooks presently used in industry are generally cast dueto the difficulty of obtaining the proper curvature at the upper portionof the eye of the hook to allow a cable to slide freely without gettingkinks or excessive wear. These cast hooks are limited in their physicalproperties and in order to get sufficient strength to the hookcomparatively high weight and large size is necessary. The cast hooksalso do not have desirable properties for shock-loading and greatvariation in strength and size is common between individual hooks.Quality control of the cast hooks is also a problem as internal defectsmake inspection diflicult.

The present invention relates to a method of making a forged choker hooktoimprove the strength and physical properties of the hook and make theproduct purchased by the consumer uniformly satisfactory. A novel methodof obtaining the proper curvature in the upper eye of the hook isdisclosed and an apparatus for performing this is also disclosed.

In performing the method according to the present invention, a chokerhook blank having a solid elongated upper eye portion is forged byconventional methods. A hole .is then drilled through this elongatedupper portion in the direction that the cable used with the choker hookmust travel. The upper end of the choker hook is then heated and placedin a die for forming a curve in the upper wall of the eye of the hook.Punches are positioned aligning with the hole and adjacent each end ofthe hole drilled through the upper portion of the choker hook. Themachine in which the die is placed is activated and a ram forces a camto actuate the punches inwardly and the punches in turn engage the eyeof the hook and form the upper wall of said eye against a forming blockhaving the desired curvature. The punches are then withdrawn and thetraveling choker hook has been completely formed. This final forming ofthe curved upper wall of the eye is done with tools that traveltransversely to the initial conventional forging dies. Previously nosatisfactory mass production forging method of performing this operationhas been advanced and casting was the only practicable way to massproduce traveling choker hooks.

The forging process of the upper eye of the hook refines the grainstructure of the steel and improves strength and toughness. The booksare much more uniform in strength and size than the previous cast hooksand the forging process results in a saving of material. In additioninternal defects, such as blowholes and inclusions, are eliminated thusmaking fewer rejects of the forged hook and more uniform qualityavailable to the users.

It is an object of the present invention to present a method for massproducing forged choker hooks that are uniform in quality and strengthand are able to withstand shock load.

It is a further object of the present invention to present a device forperforming the forging of traveling choker hooks.

In the drawings:

FIG. 1 is a side elevational view of a traveling choker hook blankbefore the upper eye has been formed;

FIG. 2 is'an end elevational view of the device of FIG. 1 as viewed fromthe right end thereof;

FIG. 3 is an end elevational view of the device of FIG. 1 after a pilothole has been drilled through the upper end portion of the hook;

.FIG. 4 is a side elevational View of a traveling choker hook after theupper eye has been forged and showing the hook, positioned on 'a cable;

FIG. 5 is an end elevational view of the device of FIG. 4 as viewed fromthe right end thereof;

FIG. 6 is a top plan View of an apparatus for forging an upper eye of atraveling choker hook with a choker hook positioned for forging before awork stroke has begun; and

FIG. 7 is a "top plan view of the device of FIG. 6 after the completionof the work stroke.

In the use of choker hooks having an eye with a curved upper wall ahoist cable passes through the eye hole and looped around the object tobe lifted. The cable end is provided with an eye that is -placed overthe hook portion of the choker hook. As the cable is hoisted it slidesthrough the hole in the hook eye and tightens or chokes down onto theobject it is lifting. In this manner the object is securely held forlifting. This method is also used for lifting piles of logs as thesliding hook allows the cable to grip the pile firmly and lift the logsas a unit.

Referring to the drawings and the numerals of reference thereon, atraveling choker hook 10 that has been formed in the blank byconventional forging methods in a three stage forging die has a hookportion 11 and an elongated eye portion 12. A hole r13 is drilledthrough the eye portion 12 parallel to the plane of the hook. The upperwall portion 14 of the choker hook eye is then formed in a curved shapeto allow the hook to slide on a cable =15 without bending or kinking thecable.

The hole 13 is transverse to the direction of travel of the forging diesused to form the hook blank and cannot be forged at the time of makingthe blank.

The upper wall of the traveling choker hook is formed in a forming die.16. The die 16 is fastened in a machine having a bed 20 and a ram block31 powered with a suitable ram (not shown). A choker hook lit with thedrilled hole 13 is heated and placed in position on a locating nest 17of the forming die 16. The eye portion 12 of the choker hook is adjacenta forming block 18 that is fixedly attached to the forming die and ismade with a curved lower surface 19 for forming the upper wall '14 ofthe choker hook eye.

The forming block 18, locating nest 17 and the choker hook it) arelocated between a first punch 21 and a second punch 22. The punches 21and 22 are slidable toward each other and are aligned with the hole 13in the choker hook eye. Each of the punches is fixedly attached to apunch adapter 23 each of which is slidable in one of a pair of guides24, 24. Each of the punch adapters has a cam follower roller 25rotatably attached thereto. First punch 21, its associated punch adapter23 and roller 25 are positioned to be actuated by a first cam plate 26.Second unch 22, its attached punch adapter 23 and roller 25 arepositioned to be actuated by a second cam plate 27. The punches arenormally urged apart by a pair of return springs 39, 349 one of which isattached to each of the punch adapters in a manner to urge the punchesaway from each other and from the forged choker hook.

An adjustment screw 33 is provided to adjust forming block 18 andlocating nest 17 to proper position with respect to the punches 21 and22. Also die wear can be compensated with the adjustment screw.

The cam plates 26 and 27 are attached to ram block 31 of the machine inwhich the die is placed and the ram block in turn is attached to asuitable source of power such as a hydraulic ram (not shown). The ramblock 31 is movable in direction as shown by arrow 32.

Operation With the choker hook blank, having the hole 13 drilledtherein, properly positioned in locating nest 17 and with hole 13aligned with punches 21 and 22 the ram block is actuated by propermechanism in direction as shown by arrow 32. v The cam plates 26 and 27act on rollers 25 as they advance and move the respective punch adaptersand punches inwardly toward each other. The punches 21 and 22 travel ina direction transverse to the direction of travel of the dies originallyused to form the hook blank. As illustrated in FIG. 7, when the ramblock has traveled a suflicient distance, the punches 21 and 22 will beforced into hole 13 and the upper wall 14 of the choker hook eye will beformed to the configuration of the lower surface 19 of forming block 18and the punches 21 and 22. The ram block 31 is then withdrawn and thereturn springs 30, 30 pull the punch adapters and their attached punchesaway from the finished choker hook. The choker hook may then be removedand the upper wall will have a configuration as illustrated in FIGS. 4and 5. With this configuration, a cable can slide easily through thechoker hook eye without kinking or bending.

The uniform properties of the forged hooks makes them safer to use andmore readily adaptable to quality control and modern inspection methods.There are no internal defects in the forged choker hooks such asblowholes or inclusions that are often found in cast products. Theforged inner surface of the upper wall 14 of the choker hook eye issmoother than the previous cast surface and results in less wear on thecable with which the hook is used.

What is claimed is:

1. A method of forming choker hooks including the steps of: forging achoker hook blank having an elongated upper eye portion parallel to theplane of the hook, drilling a hole longitudinally through said eyeportion parallel to the plane of the hook, heating said elongated eyeportion, placing said eye with the upper wall thereof adjacent a curvedforming block, and forcing complementary curved punches into said holeto cooperate with said forming block to form an upper wall of said eyeinto a longitudinally curved shape the inner wall portions defining saidhole closest to said hook remaining substantially straight.

2. A method of forging traveling choker hooks including the steps of:forging a choker hook blank having an elongated eye portion parallel tothe plane of the hook, drilling a hole longitudinally through said eyeportion parallel to the plane of the hook, heating said elongated eyeportion, placing said hook between a pair of aligned punches movable indirection toward each other and parallel to the longitudinal axis ofsaid hole, and actuating said punches to move simultaneously toward eachother and to enter said hole to deform the upper wall of said eye into alongitudinally curved shape and hold the wall portions of said eyeadjacent the hook straight.

References Cited by the Examiner UNITED STATES PATENTS 1,791,035 2/3 1Malby 29555 1,924,114 8/33 Evans 29-555 1,931,307 10/33 Taylor 153-32 X2,027,406 1/ 3 6 Spatta 7863 2,038,165 4/36 Criley 7863 2,642,112 6/53Schaefer 29551 X 2,917,033 12/59 Brogren 29551 X 2,992,465 7/61 Gale24-123 X WHITMORE A. WILTZ, Primary Examiner.

HYLAND BIZOT, JOHN F. CAMPBELL, Examiners.

1. A METHOD OF FORMING CHOKER HOOKS INCLUDING THE STEPS OF: FORGING A CHOKER HOOK BLANK HAVING AN ELONGATED UPPER EYE PORTION PARALLEL TO THE PLANE OF THE HOOK, DRILLING A HOLE LONGITUDINALLY THROUGH SAID EYE PORTION PARALLEL TO THE PLANE OF THE HOOK HEATING SAID ELONGATED EYE PORTION, PLACING SAID EYE WITH THE UPPER WALL THERE OF ADJACENT A CURVED FORMING BLOCK, AND FORCING COMPLEMENTARY CURVED PUNCHED INTO SAID HOLE TO COOPERATE WITH SAID FORMING BLOCK TO FORM AN UPPER WALL OF SAID EYE INTO A LONGITUDINALLY CURVED SHAPE THE INNER WALL PORTIONS DEFINING SAID HOLE CLOSEST TO SAID HOOK REMAINING SUBSTANTIALLY STRAIGHT. 